This invention relates generally to refrigeration and more specifically to a cooler which creates and maintains frost on articles cooled thereby, particularly in conditions where there is low moisture content in the ambient air.
Articles which must be or are most preferably kept cold, such as containers of a beverage, are frequently sold from a cooler directly accessible by the consumer. One example of such a beverage is beer, particularly as sold in glass bottles. These coolers may appear in the refrigeration isle of a supermarket or other store, or elsewhere as a point of sale display. Merchandising refrigerated articles in the summer or in locations where the weather is hot is significantly aided by conveying a consumer concept that the beverage is very cold. Conventionally, signage is used which conveys in words and/or illustrations that the products contained within are kept cold. However, such representations do not provide direct visualization to the consumer of the actual temperature of the containers.
One way providing the consumer with direct evidence that the temperature of the beverage within the container is cold, is the presence of frost on the exterior of the container. The existence of frost on the bottle immediately conveys to the consumer the concept that the product contained inside is kept cold. It is known to provide frosted glasses or other containers for receiving liquid. Generally, a wetted container is placed in an temperature controlled cooler environment where the temperature of the container is quickly dropped causing the moisture to freeze as ice on the exterior of the container. If the controlled ambient air has a sufficient moisture content, there will not be a problem in maintaining such ice or frost on the containers. However, in some situations where the ambient air has low moisture content, such as in dry or elevated regions, it is difficult to achieve or maintain the frost. Moreover, the presence of substantial moisture in the cooler can cause operating problems for the refrigeration equipment. Still further where the containers carry a liquid, it is necessary to achieve frosting without causing the liquid to freeze. Generally, for glass bottles containing beer, the exterior temperature of the bottle is maintained between about xe2x88x924xc2x0 C. and xe2x88x927.5xc2x0 C.
Among the several objects and features of the present invention may be noted the provision of a cooler which achieves and maintains a frost on articles held by the cooler; the provision of such a cooler which provides additional moisture to the interior of the cooler for condensing on the articles; the provision of such a cooler which maintains the frost on the articles during defrost of a cooling coil in the cooler; the provision of such a cooler which inhibits the circulation of warm air within an article holding zone; the provision of such a cooler which controls delivery of moist air to the article holding zone and maintains the cooler within a desired temperature operating range; the provision of such a cooler which inhibits icing of the cooling coil; the provision of such a cooler which voltage protects its components; and the provision of such a cooler which is self-contained.
Generally, a cooler of the present invention comprises an insulated cabinet defining a product zone for holding the articles to be cooled. A cooling coil constructed and arranged for receiving a coolant therethrough removes heat from the product zone in the cabinet and a fan circulates air over the cooling coil and through the product zone in the cabinet. A water vapor source in fluid communication with the product zone delivers water vapor to the zone for condensing on the articles as frost. A controller to control flow of coolant through the cooling coil, operation of the fan and operation of the water vapor source, is configured to automatically conduct a defrost mode of the cooling coil to melt any frost thereon, and to restart a cooling mode of the coil at termination of the defrost mode. The controller delays operation of the fan after restarting the cooling mode following defrost until the cooling coil has reached a preselected temperature so that the circulation of air temperature though the cabinet will not adversely affect frost on the articles.
In another aspect of the invention, a cooler for cooling articles and maintaining frost on the articles generally comprises a cabinet, cooling coil, fan, and water vapor source as set forth above. A controller is capable of controlling flow of coolant through the cooling coil, operation of the fan, and operation of the water vapor source to deliver water vapor into the cabinet for condensing on the articles as frost. The controller is configured to prevent operation of the water vapor source until after the product zone has been cooled to a pulldown temperature.
In a further aspect of the invention, a cooler for cooling articles and maintaining frost on the articles generally comprises, a cabinet having a product zone, cooling coil and fan as described above. A water vapor source in fluid communication with the product zone delivers water vapor to the product zone for condensing on the articles. The water vapor source comprises a heater for heating water to form a vapor and piping extending from the heater at least partially within the insulated wall of the cabinet and having an outlet opening into the product zone.
In still another aspect of the present invention, a cooler for cooling articles and maintaining frost on the articles generally comprises, a cabinet having a product zone, cooling coil and fan as described above. A water vapor source in fluid communication with the product zone for delivers water vapor to the product zone for condensing on the articles. The water vapor source comprises a heater for heating water to form a vapor and piping extending from the heater and having an outlet opening into the product zone. The outlet is located downstream from the cooling coil and fan within the flow of air circulated by the fan.
In another aspect of the present invention, a cooler for holding and cooling articles generally comprises a cabinet defining a cooled area in which articles can be held. A cooling coil is disposed for cooling the cooled area, and a fan circulates air over the cooling coil and through the cooled area. The cooler further includes a compressor for compressing refrigerant, a condenser for removing heat from compressed refrigerant, a control for controlling operation of the compressor, and a temperature sensor for detecting the temperature of the cooled area of the cabinet. A voltage sensor detects voltage of a power source to which the cooler can be connected. The control is configured to operate in a normal mode to turn on and off the compressor in response to the temperature of the cooled area detected by the temperature sensor and to operate in an override mode to prevent the compressor from being turned on when the voltage sensor detects that the voltage of the power source is below a predetermined minimum start voltage.
Other objects and features of the present invention will be in part apparent and in part pointed out hereinafter.